What you have is a quad breaker it's two tandems together center is a two pole 40 amp breaker with two 15 amp branch circuit breakers. If your range will work with a 40 amp circuit you should be fine.
It must be in the wall. Or hiding behind cabinets. Instead of trying to find it you could always run new wire to the new stove and install a receptacle. Who knows where they hid it.beccamac50 said:No junction box visible.